2008 Issue

UTAH ENGINEERS COUNCIL JOURNAL 19 Mr. Bhayani, a graduate from Universities of Bombay, India, and Rhode Island, Kingston, RI, worked in the consulting field before joining the Utah Division of Water Quality where he is an engineer- ing manager. He is also a registered professional engineer and a Diplomate – board certified environmental engineer – of American Academy of Environmental Engineers. He has been associated with the Council since 1991 representing the Academy. This article is excerpted from a presentation to the 8th International Specialised Conference on Small Water and Wastewater Systems, and 2nd Specialised Conference on Decentralised Water and Wastewater International Network, Coimbtore, India, February 2008. cised by the designer is respected, and the proposal may be approved subject to additional conditions and criteria. The rule usually requires a minimum design based on 300 gallons per day (1100 liters per day) per bedroom and 100 gallons per day (380 liters per day) for each ad- ditional bedroom. Other flow gen- eration rates are also available from facilities other than residences. A standard or conventional onsite system requires a minimum soil depth of 48 inches [1.2 meters] from bedrock percolating between one to 60 minutes per inch [24 minutes per centimeter] corre- sponding to 8 to 18 liters per day per square meter for trenches and one-half the rate for absorption beds, minimum separation of 24 inches [60 centimeters] between the maximum anticipated ground water and the bottom of disposal trench, and sited on a ground sloping no more than 35 percent and specified separation from land features and water bodies. Alterna- tive systems may be sited as long as minimum separation of 12 inches [30 centimeters] between the maximum anticipated ground water and the bottom of disposal trench is maintained. Packed bed systems, a part of alternative systems, may be sited in areas with minimum soil depth of 18 inches [45 centimeters] percolating between one to 120 minutes per inch [48 minutes per centimeter]. Packed bed systems may be sited in shallower soils than 18 inches [45 centimeters] provided there is no surfacing or breakthrough justified by hydro-geological and geotechnical findings. Reduction in absorption area is given when packed bed systems are installed. The review and approval authority for alternative systems is del- egated to local health departments based on satisfactory availability of resources, skills, legal and administrative support by the board. At present, no surface discharges or mechanical treatment systems are permitted for individual onsite wastewater systems. CHALLENGES Environmental sustainability is the primary objective of the board, keeping in mind fair, simple, and responsive administration of all water programs. As the pressure for development remains unabated, there will be an inevi- table need for finding alternative solutions to problems. As onsite systems assume a permanent role in wastewater infrastructure, the issues faced have realistic solu- tions. The challenges are ahead as demographic and societal trends change from the time rules were written. Rational basis of hydrau- lic design of an onsite system is always an issue. A design based on organic loading which seems more protective of water quality based on treatment capability of media seems logical. Likewise, the use of new and innovative materials and components always presents a challenge. The degree of bal- ance between performance and simplicity of operation as a factor in looking at system design is up for a debate. Performance based rules are also an option, but such change should be followed by con- tinual verification of performance. The “trust but verify” principle is very much evident in program administration and protection of public health and water quality. As the demand for water soars and sources remain stagnant, the level of recycling becomes an important issue. It is difficult to get all answers from the rule. The answers should be derived from logic, common sense and knowledge of nature. The decision balanced by logic, science and politics should be the cornerstone of any rule or program administration. In summary, the onsite program in Utah has evolved over the years fulfilling public health and water quality protection objec- tives. It will continue in the right direction to meet challenges of the future. As the demand for water soars and sources remain stagnant, the level of recycling becomes an important issue.